In March of 2021, SNS accounts for 'Trainee A' were opened and gradually six pre-debut trainees were unveiled, consisting of Inhyuk, Jihoon, Leo, James, Sangwon and a hidden member. A number of executives and producers followed their SNS accounts, sparking rumors from fans that the trainees will be the next new boy group to debut under BigHit Music.[1] Due to the large attention they have gained online, Trainee A has quickly amassed several thousands of followers across their social media accounts in less than two months.
On August 2, it was revealed that Junil had left the group.[2]
On August 22, the "About" section from the group's YouTube's channel was updated and JJ was revealed as the hidden member.
